Pancreas in young adult medaka stained with an anti-insulin antibody (green staining) (Assouline et al., 2002). (A) Sagittal section. (B) Higher-power magnification of the bracketed area in (A). The boundaries of the pancreas are shown as a dotted line. Li, liver; Bd, bile duct; In: intestine; He, heart; Sb, swim bladder (Assouline et al., 2002).